Sericominolia
A genus of marine top snails with distinctive shell and radula.
Sericominolia is a genus of sea snails, specifically marine gastropod mollusks belonging to the Trochidae family, commonly known as top snails. The shell is fairly thin and medium-sized, with a depressed, turbiniform to trochoid‑turbiniform shape, reaching up to 14.0 mm in diameter. Its whorls are rounded or only slightly shouldered, with the periphery at or below the middle of the whorl and a relatively flat base. Fine sculpture consists of closely spaced spiral lirae and microscopic axial pliculae. The umbilicus is open, with a thickened rim that usually—but not always—has a distinct internal funicle ending in a reflected callus on the columellar lip, often in a contrasting color. The outer lip is simple, and the interior is smooth.
The operculum is horny, fairly thick, and multispiral, but not tightly coiled; the whorls overlap narrowly, the peripheral fringe is narrow, and there is no spiral microsculpture. The radula has robust base‑plates on both the rachidian and lateral teeth. The inner marginal tooth is transitional, with a reduced cusp. Among the marginal teeth, cusps 3 through 10 are the largest, each bearing a broad, bluntly lanceolate central denticle that has one or two smaller denticles at its outer base. The ctenidium is bipectinate, with its anterior portion remaining unattached.
Species in the genus include *Sericominolia gloriola*, *S. lifuana*, *S. porcata*, *S. safrocincta*, *S. stearnsii*, and *S. vernicosa*. Two species have been placed into synonymy: *Sericominolia glaphyrella* is now considered a synonym of *Kanakina glaphyrella*, and *Sericominolia stearnsii* is a synonym of *Ethminolia stearnsii*.
Quick Facts
- Taxon
- Sericominolia
- Type Species
- Minolia stearnsii
- Type Species Authority
- Pilsbry, 1895
Facts from the source article.
Lore & Background
The shell of Sericominolia is relatively thin and of moderate size, with a depressed turbiniform to trochoid‑turbiniform profile, reaching a diameter of up to 14.0 mm. The whorls are rounded or only weakly shouldered, with the periphery situated at or below mid‑whorl and the base comparatively flat. The sculpture is fine and consists of close‑set spiral lirae together with microscopic axial pliculae. The umbilicus is open and has a thickened rim, usually (though not invariably) bearing a distinct internal funicle that terminates in a reflected callus on the columellar lip, often in a contrasting colour. The outer lip is simple, and the interior is smooth.
The operculum is corneous, relatively thick, and multispiral, though not tightly coiled; the whorl overlap is narrow and the peripheral fringe is also narrow, and there is no spiral microsculpture. The radula has relatively robust base‑plates on both the rachidian and lateral teeth; the inner marginal tooth is transitional, with a reduced cusp. Among the marginal teeth, cusps 3–10 are the largest and carry a broad, bluntly lanceolate central denticle that bears one to two smaller denticles at its outer base. The ctenidium is bipectinate, with the anterior portion remaining unattached.
Reader's Guide
The genus Sericominolia is significant within the family Trochidae for its combination of shell and anatomical features. The shell's open umbilicus with a thickened rim and often a contrasting internal funicle is a key diagnostic trait. The radula's robust base‑plates and the distinctive marginal teeth with a broad, bluntly lanceolate central denticle bearing smaller denticles at its outer base provide important taxonomic characters. The bipectinate ctenidium with an unattached anterior portion further distinguishes the genus. The species list includes Sericominolia gloriola, Sericominolia lifuana, Sericominolia porcata, Sericominolia safrocincta, Sericominolia stearnsii, and Sericominolia vernicosa. Some species have been brought into synonymy, such as Sericominolia glaphyrella being synonymized with Kanakina glaphyrella, and Sericominolia stearnsii being synonymized with Ethminolia stearnsii, indicating ongoing taxonomic refinement.
Did You Know?
- The shell of Sericominolia can reach a diameter of up to 14.0 mm.
- The umbilicus is open and has a thickened rim, often bearing a distinct internal funicle.
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